“担任向导”可以用英语表达为 “serve as a guide” 或 “act as a guide”。这两个短语都准确地传达了“担任向导角色”的含义。
Serve as a guide：强调作为向导提供服务或履行职责。
Act as a guide：侧重于描述行为或角色，即像向导一样行动。
在实际应用中，可以根据语境选择合适的表达。例如：
He served as a guide for the tourists during their trip.（他在旅行期间为游客担任向导。）
She acted as a guide and showed us around the museum.（她像向导一样行动，带我们参观了博物馆。）